SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '518e35654e7d5d7e57a67a032f283f58b795b55eb14240c38b6bb3e6845fef46' 
  AND token = 'ucUPsygyJjPZle+VWGaWa/qvkdG8iDbOxKpNFFtcsyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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