SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9efabd390aa7951e4159e6d34b5c20f1747c738222b44aaf308b23326de78fc0' 
  AND token = 'J3XyVrhjMExt+ViNE8gbfKLQkbN8QTh5kzUvHtmh8Fk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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