SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37099ac694f7062b02b8bd6cc24ec843acce5bfb783ef693f1a2290deff5e17a' 
  AND token = 'X3LS5CVt+qatQpXTxOKGFOPCLbCarW1LagI8IykQWBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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