SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6811691547d6567b5f9d80e42a191600b106b1c7c11157263e26f8b0ed1306f2' 
  AND token = 'GDCeUFS/r8htBwhGhZgw9vKC9SRdvoZzqXmqFHzHQQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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