SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bea4a22f86d4d554fd442cbf7218957697fc35b7a48c08b6a81b4c6d0392b422' 
  AND token = 'yebw8YrbMvjycZnysmdsKMMZzHEO65IIL8TRvbQS/Co=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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