SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8b72eed5506fa63b86ad9c4895970d2de53c4d586d360b1381ccfd96a7a3bbe' 
  AND token = 'ns70oaM/z4FEVG6Lu8uRIFQz7v4aN3xJqBSXtSrHjfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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