SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f748485b1ae902ade2eb7e9d77ad2499ecc0a80bcfe726c69900a96db8db2bd9' 
  AND token = 'Bm5RbJpLT8c7zEAK7KkEN1p5BWcroXQOvMImlrehKgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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