SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff974dd7b47d72358a577bc6d04928a26fb7078c16bf71a650c4a74c944d7d8a' 
  AND token = 'ICzsZL0u9y0Wzou30z1u6SVeHB7TVYLp50U9ESfB5a0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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