SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8df9da99341ba4e08924d641641638e0d1219966ba25ccff960a594ed172178' 
  AND token = 'cpj4YEO1GjtCWhdLW2kJTgmQ9dcQVCsTEWyp1GYbk+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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