SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '82e47d0c62e1b6436fc3fde0459bc6fe795a25826bfe2c5d3cbfc9415a3dc14b' 
  AND token = 'ONzt8k+Q3Qz7eJcFpzmkmCNI7c6gWnI7H2I6p2RL7RE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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