SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e084adbd406b6bcbaff726b1c55daff624256bdff90c987c663cb0ad8833c87e' 
  AND token = 'Qnp0Oe+rubgC8pk3QZjXjSdWgkEGegZVC4WXCDyWzAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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