SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdb04238fe906114821a03403766cc553426fd9bb41a07bb603c6e1a7bba1019' 
  AND token = '1P63kcJZtyclwT9r0a+vd560at2Yv+d4mP6dWkXHNYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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