SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6216d2d3459f6eb14d4411fbf276abdb4238ce2a15c0cc35f763761155416b5' 
  AND token = 'ceq+s5QScmRKv0qgqXYE9HBHutrqmXzqYsqQVoP8YI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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