SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48f66bc3203a6c1166d9a2c4c71d102b34735f2c33ad11bda65ec6c5ef52ba3b' 
  AND token = '3WfTgESzF0ADGO58ZDFI/IgfvSeJ86q5X85+o0eTfxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}