SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7bef59d4f7d412e536c3be91088d1b5dd8715e1ead5d6c3ca75c3e31e057d00' 
  AND token = 'zPV/VRymS0WznsAZH/12WouGThAjbGghqy62JyMQHKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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