SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '53cbe567fc466147479c750cd476dc60c896e5e1c63b71f54ca3e51b49e967dc' 
  AND token = 'PoFgZq9Wq+1w1ftArA329JS5WwuoYoKoF/zFyRQyD+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}