SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '151a9d1a64c9b07caf1ec953811692de069244132a335e46edb6f8d3fd04d92d' 
  AND token = 'SgPgE/vjkKB8P3ZvDwo5WrLfPpaNlq6KboabVhBSc7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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