SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1ea72a8f17c625dcda37563fa1832dde3c5cdf891f5ff23aa8bef09c773cbf7' 
  AND token = '3jmVCbfDtLXJYB1nrRHrzEKfOp8+5YWrMnUAEMPP9SQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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