SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3854fe37f488a8e13ebf958e1c4fec1faf5c04003885c89034aad7fb030beb5e' 
  AND token = 'yb3lKPwADyORz2u1+NBhD/KvZQKpjE52BgfL25ZlmuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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