SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c45e81cbc1dc7c27f62e2b55cfc6d9f8235ba6165e68f6568cae01af870fe181' 
  AND token = 'Phr4vmx/o5KJp1CKBxN80N+qVh2ZQPH4ggwSkW/6zxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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