SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0506e3bf4cec0d35cc775d98435383da3e9887397b6a5d1d0f2db419aed86588' 
  AND token = 'VVj4c7lMHd6lolNEhDcMyxYYcHqtkIqKZCKBFI/mDec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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