SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5016790bfcfdd7af4e710fba8b4c5448166c3a3a4c39e0b1383de22a0a7ca57' 
  AND token = 'm0OFdowWOo2kngEb13QxFprQ13JQiYBzePELM1Na+bI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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