SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c6a221861f2d06afa7fdeed683b06870e6d428990abbcb0fe40d6e44cdca6994' 
  AND token = 'h5fIOyPgylT5IiXP4IfaU7b7bsDg/v4cDSqEGiJrW0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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