SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9b77eed055759ec20b19d34718451d09fd776815df553800cd3a966c034b741' 
  AND token = 'zj6MncNGl0/vqqZW4SrImKNlB2v2iYHq9PGmeX83SKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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