SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6195306b142747bd74913dfff30229470c9ea01201dbcbe5dc807808ff4f8c8' 
  AND token = 'dZRNoNz4Bp/Uj4hlcVtCd3/fvkuWXCiDh65r4kbQk0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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