SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9c45c235e439d52114cbfbeb0fce0fbd1321a3af3f00d1cd502b7f8f6c25db2' 
  AND token = 'BZFNimhmytecC7BwAnFDm+4VUiwz2ZnSeyPQngXPfgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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