SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '752272dea02f26ff34b3ab1c14188e508964a3cf1dc36edc508936c2e18b1323' 
  AND token = 'ujIrY6dPzH5Fq+5XdNVkeEZWqwBe/E5l1O0Pd9oXzM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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