SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c89284722017f6ed65365a69e336d640143729ccad40ba4eedb79c975d9ad97' 
  AND token = 'u66b4xd0RlWcGLljoFKhz2aKG4cFEdEdIF7pKyrAHz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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