SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f20dd0264763b9b703ac613e664d79da7b6ee23c3f2778d00f38f33fc0265958' 
  AND token = 'LXzvOmgsasLLmylV5iV0wy0oBn/dJUsuBoZJwVI/NzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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