SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb9eaa948e65df8df8d0b782d62e1765bb35ff33ce232b404e3f5dd5d0931037' 
  AND token = 'PpazKrYmpT9BMmpm21IFgmFoiPQ3Bl/ApOG40hjJT14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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