SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '652b26c1a452844d44fab214cef4ba4397d6f40c2474b168cc109539a14289c1' 
  AND token = 'ZwF9RHT3YdE+UL4vplTGujQAJz3ZepNs5eVPrH1/NUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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