SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '90b3fc1fe55884ad58037dd3479dd07f9a9f6551e917819501a0ed4318cbef37' 
  AND token = 'IPlZAeG3aEhgMtG+uiDXZPs1gGCXPOYLSQgEykqP1NQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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