SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20b37c5d88f1383429586c824969e175145ed4915cdfbf71b012d29ca7dff7e1' 
  AND token = 'v4JzKLewrKyXGq35YVKR8d+BpsHy+nHq5dKFLk4GiRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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