SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b17d4ef52b5320c680fb3088e91205d3fe04938d7c6fbfc4f510aca62783a3d' 
  AND token = 'fREJM2G1BcHfs+jgVb7bPC7hcliLtsoxe6pO8clMi3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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