SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16da104cfa699da45e1236cebf2fce247e4b74056a51b7a0b70b6afc0bcfe7ea' 
  AND token = 'J059m+6LDz0XierKhfs1eefyB3mwIlzCZ7k0niaGX4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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