SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60f47bca2fd8f937252e497c3a9a8628bfdab31e4f459f711f77520570288316' 
  AND token = 'uN1T2rxW8+Uzn+gxlATtWVMyGnuPz11EC2AXNMGWHdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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