SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5177e759ead6ae73537ef68b707e40d91ceb2a767f44da5455d6bc300c640f2' 
  AND token = '2f/SiWB66RWMCHm1An5RxtXXfQ9GJQ4hP3+lMErH6hE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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