SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbe6cf8dee4032cbbcf5f5a707107b795e6c35e5ada0ff5c865bd6db2b2ceb23' 
  AND token = 'YlVUatRl0HqLbp57y+rm/o6RuRmjgMFJxCmrt+oUK1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}