SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9d11fc0544dc60ff0f062b7e5053128216f2a27bb79d7f336c3d952201589d4' 
  AND token = 'NHD6dGhO/GtIG5XP+gayZSNqMGLpAxEkB3pJZaMD7rQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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