SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36cae1db7ce271fb158de4689054e1a4b522cce16ed6cd875cc951d94392516e' 
  AND token = 'xRpIN56+rqQvxhiuPPtecHEX2Hfg/LWJeelyr9Lym74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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