SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a8baea5fecb39a1d19f3be341321751a2570b1046c4b0a498d7dcf7b1401833' 
  AND token = 'Vj9s8/MVznbALy86i3flFfAsMEExXXov7KLTO8kxLUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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