SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c4d03c615edcf80799cdaef3f6c37beb7421d279c6dc24433568e5287b4e8917' 
  AND token = 'jCwfTVo4JMR7wYF8ruqcxejsW4HI/TJYislzbAIJwb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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