SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '163191556e2ced1a82ecd265b3d2de234be86fda120f509b23e48f3855d803dc' 
  AND token = 'pvfzuPdz1Q6SlKT5SFDgF4wFAbzxyMmwAJRXeCfOMew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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