SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1eb4c9957ecc13eacc014a7796ac9fb2a3e772dcb5cd860a0ccab7f25bea4c10' 
  AND token = 'OeyzJdmm1yaw8Iz8hhcog6pNRsIAMiOwvcUJdxgurAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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