SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ce59dc97a8f9ca78dcbcd82c64a60fcfcf532bd410bf744fc93089bf4281f9b' 
  AND token = 'dgevrBlp3pSYWEAG0eJqrIZzHHBb463/aFCPdl/2JHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}