SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c96197af9ec41764798505bfaab5b6031685ecf88942bb3096288296fabecf8c' 
  AND token = 'DyMQkG3Qc4dmJzLJhtG0cmzHJn65K8XQEnCtRfWsxPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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