SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acfc3979b6614f9bb39bdd390faf7ca627461fda04677c2bbcc81b3d1facb8b7' 
  AND token = 'UoQ2VWpIHi6Ry3W89z8fzSRjXj4UminOD2P5QC2xDLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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