SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44157c87d64d46c3983eedb3008a58090ba85ea78dda9b87122f329b752a0cdb' 
  AND token = 'XDSomxHcN5XRLBSkKIt+4WzqVY8ovGVhbVSvQ4muSP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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