SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a174a97834539637e79bbf3bc91f8f9ae6a0ab5bdebfa0563f4d91f826a716a' 
  AND token = 'JhhLdKGHqv3RQZASAtOnBJYp9krKwc/5lNctpfTdEls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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