SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd048ba4b2db00bdde4f06f2f3238de56e7933ff6879eda9c38b2775c6acb0db2' 
  AND token = 'oeUbspCOLEsV853yt6wXOc27VO/KutZNbvWYOJZwmYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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