SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '860e49e77a24a7487bad3f6d37ffa029681261fb3217135c47623d928232ec12' 
  AND token = 'kOPbbwl7DywlPCwJ6fYICpqfsOD5AcpQpRzFPbGxMuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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