SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4431ba644e945a9f7c18dd8258d3eff42e505a487d30fd3e5a4b16f623f39c1' 
  AND token = '7hq4haBnDgllZKQx3eAia5o+0GqJgdhu0XUSnPGpAWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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