SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f980dc9811cc5ec7744961b93d7eb50ec75daadabcf1de8f857fad18ab867021' 
  AND token = 'aUQDnVfnyB94kQkm7eRCmPwOMWQWWRU2jvLwLrnFpNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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