SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b7441171eebefcd5323bd3f2ac02345c145544f2712e8e43faa270adb3d2a92' 
  AND token = 'M2JvEbJlhdkP25o3uKQdDXPTTgasA62ln1i3aB2pMhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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