SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '254841eecba33a5ff9860d08fc57ad750843b14d0218468352224bd6ca9f22f1' 
  AND token = 'j/6KJq/dBqiWr3Vpv78f+Da4k9IrKXjKBop5vyVEITY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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