SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9566d33c354718f1f9f65856bf4a97ef905139e282244ca2bc055333cff2f0b0' 
  AND token = 'QpL6s7F/h8KCay4MqopVpHwQeAkKYo1Ly0GqCZwNlj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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