SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55025eb34ff3f3db10e8bc8819c6b39d794dc6daa18f73ea2da9ef807cb7106d' 
  AND token = 'jHfbdmK5U0Qv5e17dpIFYjvdTgI/yIxCTQnVN+QzkXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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