SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a08fa5cae56edfdd158fbf60d62efd7849083aee095e7bb048ee6008cfbc058a' 
  AND token = 'Uy/FH4/niZhgvSGx5JhMFFryEYyxEuHQbzQ4hs2xsWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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