SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ee7b5cc78bd90c4223e2b06c0987d94bd7a4761029cf23596354da65fe8295d' 
  AND token = 'HRU6lvO8Jzw8tRNElKE4VIiB0VuBvnqOK+3fpVmq6DQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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