SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96268e31dfcd9a73e8d0128f5c2410e7fe9358e1ffda108bc3017928035793f7' 
  AND token = 'QuQeKNa706xhQRTkjl8G4mCcxBJJvvwmK8QEfB4Cmgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}