SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1281ad683117c154951e408cb97832dc9450839f1cd23d01343c2e66bcf181b' 
  AND token = 'Yb0QaXlNLU8NMzR16kZF06U9Gmsk5rPdmGWN6Z0CJJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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