SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e296b3d215fa635e2bcf5703430873b12e793e7842d8ed4ed0e888bd4a8ddd1a' 
  AND token = 'rywWaJd7xawwcot8j8PP9Z5OY1LymbCN4+elHfHXsPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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