SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35fc04f5e610354ffb23913ee39433c67ade995814e81d096a62ccf19d2c5f0e' 
  AND token = 'FKHRX2gNYkxmAzFSZzQusKtfNYFSebKCbNE2fUILocA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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