SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b3ecb92e9077368bb7fb8e034ee0cfb1e4655507b691976b0695d982a3d7dbf' 
  AND token = 'UniVCAj7iDZd/x7QrRn2SZWdQNHWr68lWme53+Kdm5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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