SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32fe6be6fb127c415cfdc862983ee5b8aead792d3cbb81f5204f7db695392102' 
  AND token = 'WgZZQmogaJcTY7AdI9mxKeKzjBV0SSukhxayXNw5IXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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