SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8dddbd5463ac8bd151119be556037d8c733c8a00bfa72b2fdd25c0d0a75248d' 
  AND token = 'NCu8HimS/TNlj+VW7k5keFD58LNmRDmFTQ4OOXKaSp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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