SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95db288892e1b0ba00fa15d5c99f4248974e794c4fa778f2635f2326dd1f487c' 
  AND token = 'VwanDqlLwQ+QDwcnGr25fgOqwFuykzsSuheDHjvsl8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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