SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c77801258eb188590061b6eacdad886eca45b7521364dbc0c8b3e8c90895d0c' 
  AND token = 'k29zhvmJIFkD7AO8oWjysasjrmlaeldbTQUwayytDhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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