SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fbfcd3ada6df0db49b0f35beda887e6caf79698eb149a1bfc3636c55087f6a3' 
  AND token = 'OtdxZEdg/h2V0cCgnCY8I7ArAXNZZe8SPcGu1rPWjxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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