SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1f19665695867410d410621bbe909431c8eeab5366f03b299729d1fdc33ab65' 
  AND token = 'JgPXNNhw246mfbrCxu6tX/MMRYFTZVwgGijzkrXSGT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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