SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a76de6aeabc9bdce7bb130c78b8a04f54fe99cbe69ad179f6e07faad3f861c0' 
  AND token = 'WHi/UXIIiQBZUMcYbe3ku2rthhjD0hDm3IEcgRh6gIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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