SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '481b205e4a0a9197d3259d5df1f10e94500c386a2839ad7b916f1c2ed13899c3' 
  AND token = '/GKnBXIB0PWXvREL9QNgPNzdE+CC70+w+2Bl3Ym52lU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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