SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46d3a031f67243bd67808c46650fd14523dcf23007a47e3793d7b8eeaafa212e' 
  AND token = 'vY7L0QBcn0xNYJMZZmEYAwDXrkXIffzEiCyqHShSFNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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