SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0090a565c47c376ab58b98ab95282ec164a8e233723ce41632db404194620573' 
  AND token = 'ZtfyvozqZIMownMdXRolgPqaSCm5JB7DFMGYgNwLGg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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