SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '569da7c94eb7a4073a48c18b27b8879cdc618df553df3f7d3e80077e019fc42e' 
  AND token = 'WWF5nDP/JyxHlN2nzWqNElOfdTR0Lc51a9vMMyrxMxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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