SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e86c6584e3516ff6480a884bbd0edbaba87a1c45753bc724001a7b512213bea8' 
  AND token = '0cd8XxVq58DpNilkQ2NxC0jBKvcL7WtWx/FvcmAvEPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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