SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '576360b519ca02c5c3801745d487da217879b0889feaca24413c2978ca0cc110' 
  AND token = 'FwYxOCxPiqS19nAEAyPRHO5e3HIauh4m+CVNSF9hUvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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