SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '78dece4f9b8e88268635fc217878fe4c1f0a7f30a0140a78363c2926a940ea6f' 
  AND token = '4krG+9WrNAA4Rmog3yVd6A4jGmyqTRGxOYU2jB6rUNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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