SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '319d86997ba2f0250abcbc5cba10209d594e1a21975df57b31d8b32f5d5f9191' 
  AND token = 'wxAqoDdK/GZVURaWTEe9NxTPBcpcxNelmHfRuYzl24c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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