SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c2a1321b3822ce7626a331e2413eecded5546556bc2d49f41927293a81f3592' 
  AND token = 'GaChzXKzcC11vKknnTvFJrgBGzGwaXGt/bNOXMMWUDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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