SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '37560f63cfb6a054b18fd1696edd30c8342467542088b3846faac430640d0712' 
  AND token = 'Pm55JCnfNwkTEyUr8qvcXubVBIBPGLKzwecwwDrM0FQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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