SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '850f0b44bffab28d983ec66fd50efba9ede305aeba93be92e035b1f172c87413' 
  AND token = 'pigJ+IqesIdAQ0xWpKfVX4+GwrfF+zYPKF9ZEMBhW3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00124

JSON explain

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