SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f91fd6146dcadb9c6d3c374a184153f66305ceea4f615848712ddef755bdfc84' 
  AND token = 'KJ+/+PS3XDDZs/p2oEzDTiWdglFWZZmptqwkKhGqaF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}