SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b66f997182e2402076728b237c0a46c597ddf2e81b40a8f04e59691f0ec2472' 
  AND token = 'PfXOZADKRjfV2AJtB51SpW2uu1X25vI8soUcjlg62SY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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