SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92a9beea214e27131d88236a33307deb29b10bcdf9659eb2903ee5d53268caf1' 
  AND token = 'KIkDO/t64Ln8uAlYsfLhy2xtZVNkxrDRWOYBpb0x7HA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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