SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac78d487685520cd4e51e6d780f86ea357d957efccc0d6f664fbf51447684fb9' 
  AND token = 'Y7E+odwFAEbJvSOirCKE5F5qJoZI0XH/9jX+X8r3l2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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