SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d28ab2a4d4b62093147c0669ebf38b0d24bfff4abf990e03d5241d10193a3d9' 
  AND token = 'qKPSP2O2dOf/qwYRT/0R8xC2/gGowxB5BS7CYWjV4QM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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