SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5acb2c8801d22f8973e80bcd1f5775ac841530d7089168f9176a67aa230d64b' 
  AND token = 'gqAMEwkxySTVnDSEba0R+LW+RE9VEpjTWKIlmYK9lrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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