SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb84eecde6305d8072a63faff60ac734f61f80ebb8a1ebf22616b7b1777f9815' 
  AND token = '+k2JzsGVvGlUGmmOuEe4iWK7LhBnfUyp0aXy4PEFZVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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