SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c55b9e34fc8497c3e6f925ddc8a5d11159a0c318f0f7d4ad885f33a03460a19' 
  AND token = 'pfmTRagjBPDtLcyeugqOxGZn4PV2V/v4shORMTMugDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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