SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4b750ccf09d256378bcf338786896ba9649d018be367f55f40640f671153eebf' 
  AND token = '5w7BH1Hf10h83f+aSxLjWigHlRyxbtK8zEGpG1bOscg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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