SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ba384eb70edcbc13ead2fa313fdafc634868ae6397a20afea96020b29db652' 
  AND token = 'kuuQDh3nXvXDqvHAcQ47tN1gWykY7yV+uY7vbeKIiu0=' 
  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"
    }
  }
}