SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b266fa3e829ac32cea29460eda05e5e2d3bbe6f37959aca0164a5308e65503a' 
  AND token = 'k4wcs0ksEUnB/alAJczHH6OBlAx0t6N8vF/Ra3EleVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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