SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86e514b514aaac4644c6c771fdadd53a88b5b1d74419cedeb784f2d5ddfb4435' 
  AND token = 'zDtqbqah+sYDSyDRvxc1jnjgrKHHlgx85muH+UITCmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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