SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '345360cd3017dab02f5f3ce02252325ca004abf1217bf7ce0612239186653fc9' 
  AND token = 'BsNQc/Xm/yvuIbaMgtaXGRbQZFVfzYWjjgVwAHFcnN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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