SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3936c13f93b43dda6575a6bea6eba4351f0082635220e10ca4ff13bedd7586d2' 
  AND token = 'pNxNcs3SEIz5vXIB9kV1psnUuBy0VeWiiJII8K3pp7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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