SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b8b34705a1becaac253b732cc3b77f7813cad44dd71afd8faf2135823693d5f' 
  AND token = '78FQfdaU1kgY+TZzX+xtpsux5Vnu8joMRB3fo8O87oA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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