SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '17a19f7544f38296c8e6f54bf818e378fc775670bd2d0f1cb40850c791d98ce7' 
  AND token = '33AXvlPlw6tfTFvH79NpnJygpCVB+axD7lb6zs45pGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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