SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da34a6d8da88b816edf209cf963840372a37ea02a77355071446393ab3eac9b0' 
  AND token = '/47QTmlIwtQHeE+4iXSPAKN9xaFveCliBnh92B7NDmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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