SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f01fb590140e3e7a250a7a1cfa9236ec31cdd83290c57cd1f82dc1d5802c9aa4' 
  AND token = 'SfZKi9+wBPB/rcOvGfgkNhH+fmhUyrV8wQ/MFwdgKZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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