SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2c733a8c8f0459eba76bf4cda2651662baae3629d0101c213637648909e726d' 
  AND token = 'fzcmc0C2ZvQiJKNxXyE9FfSzPh3B7r0ufPwIQ5wCO4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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